/*

 * fracviewer.h [from agviewer.h  (version 1.0)]

 *

 * AGV: a glut viewer. Routines for viewing a 3d scene w/ glut

 *

 * The two view movement modes are POLAR and FLYING.  Both move the eye, NOT

 * THE OBJECT.  You can never be upside down or twisted (roll) in either mode.

 *

 * A nice addition would be an examiner type trackball mode where you are

 * moving the object and so could see it from any angle.  Also less restricted

 * flying and polar modes (fly upside down, do rolls, etc.).

 *

 * Controls for Polar are just left and middle buttons -- for flying it's

 * those plus 0-9 number keys and +/- for speed adjustment.

 *

 * See agv_example.c and agviewer.c for more info.  Probably want to make

 * a copy of these and then edit for each program.  This isn't meant to be

 * a library, just something to graft onto your own programs.

 *

 * I welcome any feedback or improved versions.

 *

 * Philip Winston - 4/11/95

 * pwinston@hmc.edu

 * http://www.cs.hmc.edu/people/pwinston

 */

 /*

  * Call agvInit() with glut's current window set to the window in 

  * which you want to run the viewer. Right after creating it is fine.  It

  * will remember that window for possible later use (see below) and

  * registers mouse, motion, and keyboard handlers for that window (see below).

  *

  * allowidle is 1 or 0 depnding on whether you will let AGV install

  * and uninstall an idle function.  0 means you will not let it (because

  * you will be having your own idle function). In this case it is your

  * responsibility to put a statement like:

  *

  *     if (agvMoving)

  *       agvMove();

  *

  * at the end of your idle function, to let AGV update the viewpoint if it

  * is moving. 

  *

  * If allowidle is 1 it means AGV will install its own idle which

  * will update the viewpoint as needed and send glutPostRedisplay() to the

  * window which was current when agvInit() was called.

  *

  * agvSetIdleAllow changes this value so you can let AGV install its idle

  * when your idle isn't installed. 

  *

  */

void agvInit(int allowidle);

void agvSetAllowIdle(int allowidle);

 /*

  * Set which movement mode you are in.

  */

typedef enum { FLYING, POLAR } MovementType;

void agvSwitchMoveMode(int move);

 /*

  * agvViewTransform basically does the appropriate gluLookAt() for the 

  * current position.  So call it in your display on the projection matrix

  */

void agvViewTransform(void);

 /*

  * agvMoving will be set by AGV according to whether it needs you to call

  * agvMove() at the end of your idle function.  You only need these if 

  * you aren't allowing AGV to do its own idle.

  * (Don't change the value of agvMoving)

  */

extern int agvMoving;

void agvMove(void);

 /*

  * These are the routines AGV registers to deal with mouse and keyboard input.

  * Keyboard input only matters in flying mode, and then only to set speed.

  * Mouse input only uses left two buttons in both modes.

  * These are all registered with agvInit(), but you could register

  * something else which called these, or reregister these as needed 

  */

void agvHandleButton(int button, int state, int x, int y);

void agvHandleMotion(int x, int y);

void agvHandleKeys(unsigned char key, int x, int y);

 /*

  * Just an extra routine which makes an x-y-z axes (about 10x10x10)

  * which is nice for aligning things and debugging.  Pass it an available

  * displaylist number.

  */

void agvMakeAxesList(int displaylist);

void ncrossprod(float v1[3], float v2[3], float cp[3]);